The influence of steric hindrance effect on xanthate adsorption on sphalerite surface has been studied by adopting density functional theory (DFT). On the relaxed sphalerite (1 1 0) surface, one surface zinc atom coordinates with three sulfur atoms and is located in the center of a planar triangular structure. The sulfur atom with a large atomic radius could spatially hinder the zinc atom, which subsequently results in steric hindrance effect. Consequently, the interaction of xanthate S atoms with surface Zn has to overcome a potential barrier caused by steric hindrance effect. In addition, the DFT simulation and LST search confirmed that the replacement of surface Zn atom by Cu atom could decrease the energy barrier caused by steric hindrance effect, which is favorable for the adsorption of xanthate. The results could explain why ethyl xanthate with short chain length is hard to adsorb on the clean sphalerite surface, but can strongly adsorb on the Cu-activated sphalerite surface.

采用密度泛函理论（DFT）研究了空间位阻效应对黄药在闪锌矿表面吸附的影响。在宽松的闪锌矿上（1  1 0）表面上，一个表面锌原子与三个硫原子配位并且位于平面三角形结构的中心。原子半径大的硫原子可能会在空间上阻碍锌原子，从而导致空间位阻效应。因此，黄药S原子与表面Zn的相互作用必须克服空间位阻效应引起的势垒。另外，通过DFT模拟和LST搜索证实，用Cu原子代替表面Zn原子可以减少由位阻效应引起的能垒，有利于黄药的吸附。结果可以解释为什么链长短的黄药酸乙酯很难吸附在干净的闪锌矿表面上，却能强烈吸附在铜活化的闪锌矿表面上。